1. Field of the Invention
The present invention relates to a photographic mode selectable camera. More particularly, the present invention relates to a photographic mode selectable camera in which selection of a desired one of plural photographic modes in the camera can be effected correctly without error.
2. Description Related to the Prior Art
A lens-fitted photo film unit is known, and pre-loaded with photo film in the course of manufacture. In a very early type of the lens-fitted photo film unit, an amount of flash light of a flash device is fixed. Also, an aperture stop and shutter speed are fixed. It has been possible to use the lens-fitted photo film unit in only a very limited condition in consideration of optimizing an exposure to be taken.
There are needs of users to take photographs in various conditions with high image quality. To this end, JP-A 9-015693 and JP-A 8-184944 disclose suggested improvements of the lens-fitted photo film unit.
According to JP-A 9-015693, an aperture stop in the lens-fitted photo film unit is changed over to a large aperture stop opening in using the flash device. According to JP-A 8-184944, a shutter speed of the lens-fitted photo film unit is set slower in using the flash device. In each of those, an exposure amount can be sufficiently high even in use of the flash device of a small amount of flash light. An exposure can b taken typically by utilizing ambient light as illumination.
When the lens-fitted photo film unit according to each one of the above two documents is used to take an exposure in the daylight sync photography, an overexposure occurs. To solve this problem, JP-A 2001-215599 discloses an alternative structure of the lens-fitted photo film unit changeable between a daylight mode, a night flash mode and a daylight flash mode. In the daylight mode, the flash device is turned off, and a small aperture stop opening is set. In the night flash mode, the flash device is turned on, and a large aperture stop opening is set. In the daylight flash mode, the flash device is turned on, and the small aperture stop opening is set.
The lens-fitted photo film unit of this document has a slidable type and a depressible type of operable members. The slidable type is operated to select one of the daylight mode and the night flash mode. The depressible type is operated to set or not to set the daylight flash mode. For safety in the mode selection of a user without an error, the lens-fitted photo film unit is provided with a structure to restrict the changeover between the night flash mode and the daylight flash mode.
Furthermore, JP-A 2000-305221 discloses the lens-fitted photo film unit of which the operable member is biased by a spring toward its initial position for the purpose of preventing errors in a user s operation and ensuring precision in a selection mechanism. In this document, the spring is used to bias an aperture stop changing mechanism, by use of which the operable member is biased indirectly.
There is a type of the lens-fitted photo film unit in which a focal length and an amount of flash light are changed over at the time of close-up photography. In this type, there is linking among the operable member, a focal length changing plate and a flash light reducing plate. A toggle spring is connected with the focal length changing plate, and biases the operable member toward the initial position. Also, U.S. Pat. No. 5,950,025 (corresponding to JP-A 10-031249) discloses the lens-fitted photo film unit in which the operable member is retained on a view field changing plate of a rotatable type for a viewfinder. A toggle spring is connected with the view field changing plate, to bias the operable member toward the initial position.
Also, U.S. Pat. No. 6,154,609 (corresponding to JP-A 7-134368) discloses a construction with plural photographic modes to change over a view field of a viewfinder and an aperture size for a frame. This is in contrast with the above-mentioned JP-A 2000-305221 in which the aperture stop is changed over to a large aperture stop state at the time of flash photography.
JP-A 2000-162738 discloses three photographic modes in which the lens-fitted photo film unit is changeable. Three positions to stop the operable member are arranged in one straight direction. The operable member is slid, and is retained in one of the positions assigned to one mode desired by a user, to designate the selected one of the three photographic modes. To this end, ridges are formed for exactly positioning the operable member in its moving path.
If there are so great a number of modes at which the lens-fitted photo film unit can be set, the conditions where exposures are taken can be varied to a large extent. However, a problem arises in that the numerous modes may confuse a user who is uncertain on techniques of photography. He or she may fail to select the most suitable one of the modes in view of a scene.
In relation to the mode selection according to JP-A 2001-215599, a user is likely to commit an error in selecting one of the night flash mode and the daylight flash mode in the lens-fitted photo film unit. There is a higher probability of his or her selection of the slidable type of the operable member relevant to the daylight mode, to determine the night flash mode. This may cause a problem of occurrence of overexposure even in the product changeable in the numerous photographic modes.
In view of the foregoing problems, an object of the present invention is to provide a photographic mode selectable camera in which selection of an intended one of plural photographic modes can be effected correctly by reducing probability of errors in the selection.
In order to achieve the above and other objects and advantages of this invention, a photographic mode selectable camera is provided, the camera including a flash unit for applying flash light to a photographic object, and an exposure amount changer for changing over object light incident on photo film from the object between low and high exposure amounts. The photographic mode selectable camera includes a movable selector for designating a selected one of a daylight mode, a daylight flash mode and a night flash mode, wherein the movable selector, when the daylight mode is designated, sets the exposure amount changer at the low exposure amount and turns off the flash unit, and when the daylight flash mode is designated, sets the exposure amount changer at the low exposure amount and turns on the flash unit, and when the night flash mode is designated, sets the exposure amount changer at the high exposure amount and turns on the flash unit. The movable selector is externally operable between first, second and third set positions, designates the daylight mode when in the first set position, designates the daylight flash mode when in the second set position, and designates the night flash mode when in the third set position, and the second set position is located between the first and third set positions.
The camera further includes an aperture stop opening for passing the object light from the object toward the photo film. The exposure amount changer includes an aperture stop mechanism for changing over the aperture stop opening between large and small aperture stop states, for selecting the small aperture stop state when the daylight mode or the daylight flash mode is designated, and for selecting the large aperture stop state when the night flash mode is designated.
The camera further includes a shutter mechanism for providing the photo film with an exposure. The exposure amount changer further includes a shutter speed changing mechanism for changing over a shutter speed of the shutter mechanism between high and low shutter speeds, selects the high shutter speed when the daylight mode or the daylight flash mode is designated, and selects the low shutter speed when the night flash mode is designated.
The camera further includes a flash light amount adjustor for changing over the flash light of the flash unit between large and small light amounts, for selecting the large light amount when the daylight flash mode is designated, and for selecting the small light amount when the night flash mode is designated.
The camera is a lens-fitted photo film unit pre-loaded with the photo film.
The movable selector comprises a movable, external operable member. Furthermore, a first guide mechanism guides the external operable member in a first moving path between the first and second set positions. A second guide mechanism guides the external operable member in a second moving path between the second and third second set positions, wherein the second moving path extends angularly from the first moving path at the second set position.
The first guide mechanism includes a first guide plate secured to one of the second guide mechanism and the camera. A first guide opening is formed in the first guide plate, and having an edge extending along the first moving path. A first guide projection is formed to project from a remaining one of the second guide mechanism and the camera, for movably contacting the edge of the first guide opening to be guided. The second guide mechanism includes a second guide plate secured to one of the first guide mechanism and the external operable member. A second guide opening is formed in the second guide plate, and having an edge extending along the second moving path. A second guide projection is formed to project from a remaining one of the first guide mechanism and the external operable member, for movably contacting the edge of the second guide opening to be guided.
The edge of the first guide opening extends along a straight line, the first guide projection is slidable, the edge of the second guide opening extends along an arc, and the second guide projection is rotatable.
The first guide projection projects from the camera, the second guide plate is secured to the first guide plate, and the second guide projection projects from the external operable member.
In one preferred embodiment, the third set position is located externally from the first and second set positions, and the external operable member is pulled outwards when shifted from the second set position to the third set position.
The external operable member includes first and second edge portions. The first guide mechanism includes a slider slidable between first and second positions that correspond to respectively the first and second set positions. The second guide mechanism includes a rotational support mechanism for securing the first edge portion of the external operable member to the slider, and for supporting the external operable member on the slider in a rotatable manner between the second and third set positions, wherein the external operable member is shifted to the third set position by external operation to pull outwards the second edge portion.
In another preferred embodiment, the camera includes an outer cover. The first guide mechanism includes a first gap portion, formed in the outer cover to extend along the first moving path, for guiding the external operable member between the first and second set positions in a slidable manner. The second guide mechanism includes a second gap portion, formed in the outer cover to extend along the second moving path from an edge of the first gap portion, for guiding the external operable member between the second and third set positions in a slidable manner.
In still another preferred embodiment, the third set position is located internally from the first and second set positions, and the external operable member is depressed inwards when shifted from the second set position to the third set position.
In another preferred embodiment, the movable selector comprises an external operable member movable between the first to third positions. Furthermore, a first slidable member is secured to an inside of the external operable member, and slidable between first to third positions that correspond to respectively the first to third set positions. A second slidable member is slidable along a sliding path of the first slidable member. A linking mechanism links the first slidable member with the second slidable member in a removable manner, for disengagement with resiliency upon sliding of the first slidable member from the second position toward the third position, to allow the first slidable member to move independently from the second slidable member, and for engagement again with resiliency upon sliding of the first slidable member from the second position toward the first position, to allow the first slidable member to move together with the second slidable member, whereby the second slidable member shifts in a range corresponding to a section defined between the first and second set positions.
In a further preferred embodiment, the movable selector comprises an external operable member movable between the first to third set positions. Furthermore, a lock mechanism is movable between a releasing position and a locking position, for allowing the external operable member to move from the second set position to the third set position when in the releasing position, and for blocking movement of the external operable member from second set position toward the third set position when in the locking position.
The first to third set positions are arranged substantially along a straight line.
Furthermore, a sync switch is pressed and curved by a portion of the shutter blade in movement of the shutter blade from the shut position toward the open position, for being turned on. The shutter speed changing mechanism sets a curved amount of the sync switch stepwise at a selected one of large and small amounts, so as to set each of the low and high shutter speeds.
The shutter speed changing mechanism includes a pad movable to and from a position behind the sync switch, wherein the pad, when the high shutter speed is set, is positioned behind the sync switch to set the curved amount of the sync switch at the small amount, and when the low shutter speed is set, is positioned away from behind the sync switch to set the curved amount of the sync switch at the large amount.
According to one aspect of the invention, a camera includes guide means for temporarily retaining the mode selection operable member in the second set position in moving the mode selection operable member from the first set position to the second set position, and for setting a second shift of the mode selection operable member discontinuous from a first shift thereof, wherein the first shift is defined between the first and second set positions, and the second shift is defined between the second and third set positions.
According to another aspect of the invention, the movable selector includes a first external operable member, shiftable between first and second set positions, for designating the daylight mode when in the first set position, and for designating the daylight flash mode when in the second set position. A second external operable member is shiftable between third and fourth set positions, for designating the night flash mode when in the third set position, and for canceling designation of the night flash mode when in the fourth set position.
The second external operable member is movable when the first external operable member is in the second set position.
Moving paths of the first and second external operable members overlap on each other at least partially. The first external operable member, when in the first set position, locks the second external operable member in the fourth set position, and when in the second set position, allows the second external operable member to move to the third set position.
The moving paths of the first and second external operable members are collinear with each other.
In one preferred embodiment, the moving paths of the first and second external operable members extend angularly from each other.
In another preferred embodiment, the first external operable member is movable along a first moving path, and the second external operable member is movable along a second moving path extending in a direction different from the first moving path.
In still another preferred embodiment, moving paths of the first and second external operable members extend along each other.
In another preferred embodiment, a moving path of one of the first and second external operable members extends along a straight line, and a moving path of a remaining one of the first and second external operable members is curved.
In a further preferred embodiment, one of the first and second external operable members is depressible in a pushbutton fashion with reference to a moving path of a remaining one of the first and second external operable members.